kiji-express: EXP-455. Update to reflect changes made in SCHEMA-775

issue: https://jira.kiji.org/browse/EXP-455
review: https://review.kiji.org/r/1933
commit: https://github.com/kijiproject/kiji-express/commit/c53767c80eae9c108077038a5061b0a36e1955b8